RIM’s BlackBerry PlayBook is our best look so far at a preview of what we can expect from the forthcoming platform-switch over to BlackBerry 10. There have been some pretty interesting developments for the tablet so far, like the introduction of support for interpreting Android apps. That seemed like a boon for the OS, potentially giving users access to a whole different world of apps. On the BlackBerry side, though, that world looks like it’s about to get just a bit smaller. RIM VP Alec Saunders took to Twitter recently to confirm that RIM will be removing the ability to sideload apps from PlayBook OS.

Saunders defends the need to remove sideloading as a response to piracy. From the sounds of it, it’s not just native apps that will have to be installed through App World, but re-packaged Android apps as well. If the change isn’t ready in time for the next PlayBook OS update, it will be in the one following it.

RIM admittedly has a big problem with app availability, but is an Apple-style lockdown the solution? Based on the commentary in Saunders’ Twitter feed, users are generally opposed to the removal of sideloading privileges, but seem like they’d be tolerant if this meant that RIM could get some higher-profile developers to port their titles to the platform. We’re curious if the company’s decision will really influence developers any, since the kind of apps users are clamoring for (Netflix et al) largely aren’t the kind that are vulnerable to piracy.

Presumably, we’ll be looking at the same kind of restrictions in BlackBerry 10.